chore: use github.com/rogpeppe/go-internal/diff

Author: ldez

go.mod

@@ -45,7 +45,7 @@ require (
 	github.com/gofrs/flock v0.12.1
 	github.com/golangci/dupl v0.0.0-20180902072040-3e9179ac440a
 	github.com/golangci/go-printf-func-name v0.1.0
-	github.com/golangci/gofmt v0.0.0-20241223200906-057b0627d9b9
+	github.com/golangci/gofmt v0.0.0-20250106114630-d62b90e6713d
 	github.com/golangci/misspell v0.6.0
 	github.com/golangci/plugin-module-register v0.1.1
 	github.com/golangci/revgrep v0.5.3

go.sum

@@ -1,11 +1,16 @@
 package gofmt
 
 import (
+	"bytes"
 	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
 
-	gofmtAPI "github.com/golangci/gofmt/gofmt"
+	"github.com/rogpeppe/go-internal/diff"
 	"golang.org/x/tools/go/analysis"
 
+	"github.com/golangci/gofmt/gofmt"
 	"github.com/golangci/golangci-lint/pkg/config"
 	"github.com/golangci/golangci-lint/pkg/goanalysis"
 	"github.com/golangci/golangci-lint/pkg/golinters/internal"
@@ -21,14 +26,23 @@ func New(settings *config.GoFmtSettings) *goanalysis.Linter {
 		Run:  goanalysis.DummyRun,
 	}
 
+	var options gofmt.Options
+	if settings != nil {
+		options = gofmt.Options{NeedSimplify: settings.Simplify}
+
+		for _, rule := range settings.RewriteRules {
+			options.RewriteRules = append(options.RewriteRules, gofmt.RewriteRule(rule))
+		}
+	}
+
 	return goanalysis.NewLinter(
 		linterName,
 		"Checks if the code is formatted according to 'gofmt' command.",
 		[]*analysis.Analyzer{analyzer},
 		nil,
 	).WithContextSetter(func(lintCtx *linter.Context) {
 		analyzer.Run = func(pass *analysis.Pass) (any, error) {
-			err := runGofmt(lintCtx, pass, settings)
+			err := run(lintCtx, pass, options)
 			if err != nil {
 				return nil, err
 			}
@@ -38,29 +52,37 @@ func New(settings *config.GoFmtSettings) *goanalysis.Linter {
 	}).WithLoadMode(goanalysis.LoadModeSyntax)
 }
 
-func runGofmt(lintCtx *linter.Context, pass *analysis.Pass, settings *config.GoFmtSettings) error {
-	var rewriteRules []gofmtAPI.RewriteRule
-	for _, rule := range settings.RewriteRules {
-		rewriteRules = append(rewriteRules, gofmtAPI.RewriteRule(rule))
-	}
-
+func run(lintCtx *linter.Context, pass *analysis.Pass, options gofmt.Options) error {
 	for _, file := range pass.Files {
 		position, isGoFile := goanalysis.GetGoFilePosition(pass, file)
 		if !isGoFile {
 			continue
 		}
 
-		diff, err := gofmtAPI.RunRewrite(position.Filename, settings.Simplify, rewriteRules)
-		if err != nil { // TODO: skip
-			return err
-		}
-		if diff == nil {
+		if !strings.HasSuffix(position.Filename, ".go") {
 			continue
 		}
 
-		err = internal.ExtractDiagnosticFromPatch(pass, file, string(diff), lintCtx)
+		input, err := os.ReadFile(position.Filename)
+		if err != nil {
+			return fmt.Errorf("unable to open file %s: %w", position.Filename, err)
+		}
+
+		output, err := gofmt.Source(position.Filename, input, options)
 		if err != nil {
-			return fmt.Errorf("can't extract issues from gofmt diff output %q: %w", string(diff), err)
+			return fmt.Errorf("error while running goimports: %w", err)
+		}
+
+		if !bytes.Equal(input, output) {
+			newName := filepath.ToSlash(position.Filename)
+			oldName := newName + ".orig"
+
+			theDiff := diff.Diff(oldName, input, newName, output)
+
+			err = internal.ExtractDiagnosticFromPatch(pass, file, string(theDiff), lintCtx)
+			if err != nil {
+				return fmt.Errorf("can't extract issues from goimports diff output %q: %w", string(theDiff), err)
+			}
 		}
 	}
 

pkg/golinters/gofmt/gofmt.go

@@ -3,11 +3,11 @@ package gofumpt
 import (
 	"bytes"
 	"fmt"
-	"io"
 	"os"
+	"path/filepath"
 	"strings"
 
-	"github.com/shazow/go-diff/difflib"
+	"github.com/rogpeppe/go-internal/diff"
 	"golang.org/x/tools/go/analysis"
 	"mvdan.cc/gofumpt/format"
 
@@ -19,13 +19,7 @@ import (
 
 const linterName = "gofumpt"
 
-type differ interface {
-	Diff(out io.Writer, a io.ReadSeeker, b io.ReadSeeker) error
-}
-
 func New(settings *config.GofumptSettings) *goanalysis.Linter {
-	diff := difflib.New()
-
 	var options format.Options
 
 	if settings != nil {
@@ -49,7 +43,7 @@ func New(settings *config.GofumptSettings) *goanalysis.Linter {
 		nil,
 	).WithContextSetter(func(lintCtx *linter.Context) {
 		analyzer.Run = func(pass *analysis.Pass) (any, error) {
-			err := runGofumpt(lintCtx, pass, diff, options)
+			err := run(lintCtx, pass, options)
 			if err != nil {
 				return nil, err
 			}
@@ -59,7 +53,7 @@ func New(settings *config.GofumptSettings) *goanalysis.Linter {
 	}).WithLoadMode(goanalysis.LoadModeSyntax)
 }
 
-func runGofumpt(lintCtx *linter.Context, pass *analysis.Pass, diff differ, options format.Options) error {
+func run(lintCtx *linter.Context, pass *analysis.Pass, options format.Options) error {
 	for _, file := range pass.Files {
 		position, isGoFile := goanalysis.GetGoFilePosition(pass, file)
 		if !isGoFile {
@@ -77,18 +71,14 @@ func runGofumpt(lintCtx *linter.Context, pass *analysis.Pass, diff differ, optio
 		}
 
 		if !bytes.Equal(input, output) {
-			out := bytes.NewBufferString(fmt.Sprintf("--- %[1]s\n+++ %[1]s\n", position.Filename))
-
-			err := diff.Diff(out, bytes.NewReader(input), bytes.NewReader(output))
-			if err != nil {
-				return fmt.Errorf("error while running gofumpt: %w", err)
-			}
+			newName := filepath.ToSlash(position.Filename)
+			oldName := newName + ".orig"
 
-			diff := out.String()
+			theDiff := diff.Diff(oldName, input, newName, output)
 
-			err = internal.ExtractDiagnosticFromPatch(pass, file, diff, lintCtx)
+			err = internal.ExtractDiagnosticFromPatch(pass, file, string(theDiff), lintCtx)
 			if err != nil {
-				return fmt.Errorf("can't extract issues from gofumpt diff output %q: %w", diff, err)
+				return fmt.Errorf("can't extract issues from gofumpt diff output %q: %w", string(theDiff), err)
 			}
 		}
 	}

pkg/golinters/gofumpt/gofumpt.go

@@ -5,4 +5,4 @@ import "fmt"
 
 func GofumptNewLine() {
 	fmt.Println( "foo" ) // want "File is not properly formatted"
-} // want "File is not properly formatted"
+}

pkg/golinters/gofumpt/testdata/gofumpt.go

@@ -1,9 +1,12 @@
 package goimports
 
 import (
+	"bytes"
 	"fmt"
+	"os"
+	"path/filepath"
 
-	goimportsAPI "github.com/golangci/gofmt/goimports"
+	"github.com/rogpeppe/go-internal/diff"
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/imports"
 
@@ -31,7 +34,7 @@ func New(settings *config.GoImportsSettings) *goanalysis.Linter {
 		imports.LocalPrefix = settings.LocalPrefixes
 
 		analyzer.Run = func(pass *analysis.Pass) (any, error) {
-			err := runGoImports(lintCtx, pass)
+			err := run(lintCtx, pass)
 			if err != nil {
 				return nil, err
 			}
@@ -41,24 +44,33 @@ func New(settings *config.GoImportsSettings) *goanalysis.Linter {
 	}).WithLoadMode(goanalysis.LoadModeSyntax)
 }
 
-func runGoImports(lintCtx *linter.Context, pass *analysis.Pass) error {
+func run(lintCtx *linter.Context, pass *analysis.Pass) error {
 	for _, file := range pass.Files {
 		position, isGoFile := goanalysis.GetGoFilePosition(pass, file)
 		if !isGoFile {
 			continue
 		}
 
-		diff, err := goimportsAPI.Run(position.Filename)
-		if err != nil { // TODO: skip
-			return err
-		}
-		if diff == nil {
-			continue
+		input, err := os.ReadFile(position.Filename)
+		if err != nil {
+			return fmt.Errorf("unable to open file %s: %w", position.Filename, err)
 		}
 
-		err = internal.ExtractDiagnosticFromPatch(pass, file, string(diff), lintCtx)
+		output, err := imports.Process(position.Filename, input, nil)
 		if err != nil {
-			return fmt.Errorf("can't extract issues from goimports diff output %q: %w", string(diff), err)
+			return fmt.Errorf("error while running goimports: %w", err)
+		}
+
+		if !bytes.Equal(input, output) {
+			newName := filepath.ToSlash(position.Filename)
+			oldName := newName + ".orig"
+
+			theDiff := diff.Diff(oldName, input, newName, output)
+
+			err = internal.ExtractDiagnosticFromPatch(pass, file, string(theDiff), lintCtx)
+			if err != nil {
+				return fmt.Errorf("can't extract issues from goimports diff output %q: %w", string(theDiff), err)
+			}
 		}
 	}